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# Apache Cassandra 2.x CQL binding

Binding for [Apache Cassandra](http://cassandra.apache.org), using the CQL API
via the [DataStax
driver](http://docs.datastax.com/en/developer/java-driver/2.1/java-driver/whatsNew2.html).

To run against the (deprecated) Cassandra Thrift API, use the `cassandra-10` binding.

## Creating a table for use with YCSB

For keyspace `ycsb`, table `usertable`:

    cqlsh> create keyspace ycsb
        WITH REPLICATION = {'class' : 'SimpleStrategy', 'replication_factor': 3 };
    cqlsh> USE ycsb;
    cqlsh> create table usertable (
        y_id varchar primary key,
        field0 varchar,
        field1 varchar,
        field2 varchar,
        field3 varchar,
        field4 varchar,
        field5 varchar,
        field6 varchar,
        field7 varchar,
        field8 varchar,
        field9 varchar);

**Note that `replication_factor` and consistency levels (below) will affect performance.**

## Cassandra Configuration Parameters

- `hosts` (**required**)
  - Cassandra nodes to connect to.
  - No default.

* `port`
  * CQL port for communicating with Cassandra cluster.
  * Default is `9042`.

- `cassandra.keyspace`
  Keyspace name - must match the keyspace for the table created (see above).
  See http://docs.datastax.com/en/cql/3.1/cql/cql_reference/create_keyspace_r.html for details.

  - Default value is `ycsb`

- `cassandra.username`
- `cassandra.password`
  - Optional user name and password for authentication. See http://docs.datastax.com/en/cassandra/2.0/cassandra/security/security_config_native_authenticate_t.html for details.

* `cassandra.readconsistencylevel`
* `cassandra.writeconsistencylevel`

  * Default value is `ONE`
  - Consistency level for reads and writes, respectively. See the [DataStax documentation](http://docs.datastax.com/en/cassandra/2.0/cassandra/dml/dml_config_consistency_c.html) for details.
  * *Note that the default setting does not provide durability in the face of node failure. Changing this setting will affect observed performance.* See also `replication_factor`, above.

* `cassandra.maxconnections`
* `cassandra.coreconnections`
  * Defaults for max and core connections can be found here: https://datastax.github.io/java-driver/2.1.8/features/pooling/#pool-size. Cassandra 2.0.X falls under protocol V2, Cassandra 2.1+ falls under protocol V3.
* `cassandra.connecttimeoutmillis`
* `cassandra.readtimeoutmillis`
  * Defaults for connect and read timeouts can be found here: https://docs.datastax.com/en/drivers/java/2.0/com/datastax/driver/core/SocketOptions.html.